The long-term objectives of this project are (1) to elucidate the natural history and mechanism of oncogenesis by herpesvirus using the Lucke tumor as a model system, and (2) to gain an understanding at the molecular level of viral and cellular regulatory mechanisms using frog virus 3 (FV 3) as a model system. We continue our efforts to grow the Lucke herpesvirus in vitro and if successful will characterize LHV physically, chemically, and immunologically. Its interaction with host cells in vitro and in vivo will also be studied with special emphasis on the role of temperature. FV 3 studies will deal with isolation and characterization of virion structural proteins and determination of their functions. The mechanism of FV 3 inhibition or permissiveness of heterologous viral nucleic acid synthesis (e.g., VSV, Sindbis virus) in co-infected cells will be determined. Transcriptional and translational regulation of FV 3 gene expression in FV 3 infected cells will be analyzed. These studies will include the role of DNA-binding proteins in FV 3 gene expression and DNA replication. Additional ts mutants will be isolated, characterized, and used to help identify viral gene functions as related to the above.